Device for supporting the thread guide of an automatic flat knitting machine

ABSTRACT

The device is fitted to a flat knitting machine that comprises a carriage moving in a horizontal plane above two needle beds and featuring anchor plates that are able to move in a vertical plane. 
     The device comprises a series of slides coupled with a bar, located above the needle beds, and provided with thread guides, each slide featuring a track in which two facing ledges are formed that can be struck by one of the anchor plates, consequently causing the slide to be drawn along. Two rockers pivot upon the slide, each of the these comprising two arms first and second, which respectively work in conjunction with a related ledge and a related side of the slide. 
     If the second arm is kept alongside the side, the anchor plate is prevented from striking against the ledge whilst when the same second arm is moved away from the side the anchor plate strikes against the ledge.

BACKGROUND OF THE INVENTION

The present invention concerns the technical sector covering knittingmachines and is particularly referred to a device for supporting thethread guide of these machines.

DESCRIPTION OF THE PRIOR ART

Known knitting machines comprise two needle beds, located symmetricallyto one another, above which a carriage moves, during its movementcausing the needles in the needle beds to be selected following a presetprogram, also feeding out the thread coming from the various differentbobbins to the set of needles.

These knitting machine feature bars for this latter operation which arelocated above the needle beds, parallel to one another and to the saidneedle beds, and slides, which are able to move along these bars, andfeature the same number of thread guides, with functions known toexperts in the sector.

The above-mentioned carriage features vertically movable anchor platesthat are able to strike the selected slides and move them along togetherwith the carriage itself.

The stroke of the slides is limited by stops which can be locked inposition on the same bars, these stops being shaped so as to enable theabove-mentioned anchor plates to gradually disengage from them, and tostop the related slide in both the carriage's directions of movement.

A first known form of producing the above-mentioned components isillustrated in FIGS. 1a and 1b in the enclosed drawings, in which twocharacteristic situations of the slides, respectively moving andstopped, are shown.

In these FIGS. 1 indicates a slide, one face of which features a groove,that couples in complementary fashion with the said bar, while a threadguide of known type, not illustrated, is locked to the opposite face ofthe slide 1, extending towards the needle beds below (not illustrated).

The upper edge 1a of the slide 1 forms a track P, whose profile issymmetrical in relation to the direction of movement of the carriage(not illustrated) of a knitting machine.

Anchor plates 50 work in conjunction with the above-mentioned carriage,these anchor plates taking up a raised or lowered vertical position(delimited using known means) which respectively cause the same anchorplate 50 to strike or not strike the track P of the slide 1 below it.

It should be emphasised that the above-mentioned known means delimitingthe lowered position of the anchor plate 50 permit the latter a measureof "elastic excursion" in the direction of the raised position, enablingit to follow the profile of the aforementioned track P until reachingthe related ledge 1b, formed in the same track P for each of the twodirections of movement S, M of the carriage; the said slide 1 thus beingdrawn along together with the aforementioned carriage (FIG. 1a).

The distance moved by the slide 1 is limited, in each direction ofmovement S, M, by a stop 3, comprising a bracket 4 upon which a cam 5 ismounted.

In the example described, the stop 3 delimiting the end of strokeposition in direction of movement S is considered.

The bracket 4 is removably mounted on the aforementioned bar 2 in thedesired position in which the slide 1 stops when striking against thesame bracket 4.

The cam 5, which operates beside the above-mentioned track P, is shapedin such a way as to enable the anchor plate 50 to gradually disengagefrom the aforementioned ledge 1b during the last stretch of the strokeof slide 1, by means of a first ramp 5a which lifts the anchor plate 50itself, also enabling it to move over the above-mentioned bracket 4(FIG. 1b).

The same cam 5 features a second ramp 5b, which enables the same anchorplate 50 to move over the bracket 4 during its stroke in the oppositedirection immediately before engaging with the slide 1.

As can easily be deduced, it is possible for a slide 1 to be located inthe section between two consecutive stops 3 in the known solutiondescribed above.

As a consequence the range of operating processes possible in theknitting machines incorporating the above-mentioned components isnecessarily limited; in other words the above solution is acceptable forcarriages fitted with only one operating unit.

A second known form of producing the above components is shown in theenclosed tables of drawings, in FIGS. 2a, 2b, 2c, which enables twoslides to be fitted in each of the said sections between two consecutivestops; this is required on carriages featuring two identical operatingunits that are mounted beside one another. In order to effect this thecomponents must not only comprise the slides described below, but also afurther anchor plate, working in conjunction with each bar, in additionto those already present in the example above.

With reference to the said figures, 2 indicates a bar, identical to theprevious one, to which a stop 3, similar to the one described above, isfixed.

The stop 3 delimits the end of stroke position on one side of two slides10, 11, first and second respectively, for one direction of movement Mof the carriage mounting two anchor plates 50a, 50b, with the said firstanchor plate 50a operating with the aforesaid first slide 10, and withthe second anchor plate 50b operating with the second slide 11.

The aforementioned slides 10 and 11 differ from one another, and fromthe above-mentioned slide 1, only where their upper ribs 10a and 11a,forming the same number of tracks P1 and P2, are concerned.

The upper ribs 10a, 11a, whose profiles are symmetrical to one anotherin relation to the direction of the movement of the aforesaid carriage,feature ledges 10b and 11b which serve the same function as ledges 1bdescribed above.

The aforementioned tracks also feature two projections 10c and 11c whichprotrude from the related slides 10 and 11 and face one another.

The said projection 10c is aligned with the cam 5 of stop 3, while theprojection 11c is aligned with the upper ribs 10a, 11a.

In this way it is possible for the said projections 10c, 11c to crossover, and for the above slides 10, 11 to move beside one another.

In FIG. 2a the first slide 10 is illustrated in its end of strokeposition, which is to say stopped up against the stop 3, with therelated anchor plate 50a disengaged from the corresponding ledge 10b.

In FIG. 2b, the second slide 11 is illustrated drawn along by therelated anchor plate 50b, the latter being engaged with thecorresponding ledge 11b, just before the aforementioned projections 10c,11c cross over.

In FIG. 2c, the second slide 11 is illustrated at the end of its strokebehind the first slide 10, with the related anchor plate 50b disengagedfrom the ledge 11b as a result of the fact that the above-mentionedprojections have crossed over. In the same way the same anchor plate 50bwill be disengaged during a subsequent stage, not illustrated, by thefirst slide 10 as well as by the stop 3.

A first disadvantage of this second form of producing the componentsconsists in the fact that it is impossible to increase the number ofslides in each section between two consecutive stops beyond two, incontrast to more sophisticated machines whose carriages feature three ormore independent operating units.

A second disadvantage results from the fact that the slides 10, 11, aswell as the stops 3, differ from one another, thus leading to bothhigher production costs and higher warehouse costs.

SUMMARY OF THE INVENTION

The object of the present invention is to propose a universal threadguide support device that is able to fulfil its related function in bothdirections of movement of the carriage, and to be fitted in any numberwhatsoever in the sections between two stop brackets immovably mountedon the same bar.

The above objects are obtained proceeding in accordance with thatproposed in claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics of the present invention are emphasised hereinafterwith specific reference to the enclosed drawings, in which:

FIGS. 1a and 1b illustrate a first known form of producing theabove-mentioned components with the slides in two characteristicsituations, respectively moving and stopped;

FIG. 2a illustrates the disengagement of the first anchor plate 50a fromthe corresponding first slide 10 at the end of the latter's stroke;

FIG. 2b illustrates the second slide 11, drawn along by the secondanchor plate 50b, before it is stopped;

FIG. 2c illustrates the disengagement of the of the second anchor platefrom the second slide at the end of the latter's movement behind thefirst slide;

FIG. 3 is an illustration in perspective of the slide which is thesubject of the present invention;

FIGS. 4a, 4b, 4c, 4d, 4e, 4f are diagrammatic side views of the mostimportant operating stages of a series of slides mounted so that itcouples with a bar.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to the said figures, 2 indicates a bar, located above theneedle beds 70 of a knitting machine, upon which a slide 100, the objectof the present invention, is mounted in such a way that it couples withand is able to slide along the bar 2.

This is made possible by the fact that one face of the body 101 of theslide 100 features a horizontal groove that couples in complementaryfashion with the bar 2, in a similar way to the slides of known typedescribed above. The opposite face of the body 101 features a verticalgroove which is designed to receive the upper portion 60a of a threadguide 60, of known type, that extends towards the needle beds 70 below.

The upper rib 101a of the slide 100 forms a track P3, whose profile issymmetrical in relation to the direction of movement of the carriage 90(directions S, M) of a knitting machine.

The above-mentioned track P3 features two ledges 101b, each of whichserve for one direction of movement of the carriage 90; the latterfeatures anchor plates 50 which, when in their lowered position, strikeagainst the aforesaid ledges 101b in order to draw along the slide 100;the stroke through which this latter moves being delimited, in each ofthe aforementioned directions of movement, by a stop 3 comprising abracket 4 which is removably mounted on the bar 2.

Two rockers 40, each of which operates in conjunction with one of theabove-mentioned ledges 101b, are mounted in a symmetrical position sothat they pivot near the upper rib 101a on the aforesaid body 101.

Each rocker 40 comprises two arms 41, 42, first and second respectively,the first arm 41 of which extends beside the above-mentioned track P3,beyond the corresponding ledge 101a towards the centre of theaforementioned body 101, and the second arm 42 of which extendsdownwards by the side 101c of the same body 101.

The end of the first arm 41 is tapered, forming a first ramp 41a forrising above the aforementioned ledge 101b.

A boot 43 in shock-absorbing elastic material is fitted to the free endof the second arm 42.

The rocker 40 features a second ramp 44 between the above-mentioned arms41, 42, designed to be gradually borne upon by the aforementioned anchorplate, acting on the above-mentioned track P3.

The second ramp 44 slants in the opposite direction to theaforementioned first ramp 41a (FIG. 3).

Each rocker 40 is able to turn through a predetermined angle around theaxis of the above-mentioned pivot from a first position T to a secondposition R, and vice versa.

In the said first position T, the first arm 41 is aligned with theaforesaid track P3, and the second arm 42 is situated alongside side101c of the body 101.

In the aforementioned second position R, the first arm 41 is loweredwhilst the second arm 42 is moved away from the aforesaid side 101c.

The above-mentioned rotation can alternatively be free, prevented oractively effected following the modes described below.

FIG. 4a illustrates, by way of example, four slides 100a, 100b, 100c,100d, first, second, third and fourth respectively, that are situated upagainst one another, with the said fourth slide 100d in its turn beingstopped up against one of the above-mentioned stops 3 present on the bar2.

FIG. 4a also illustrates a first anchor plate 50a, in the loweredposition, moving in direction M, close to the aforesaid stop 3.

FIG. 4b shows the above-mentioned first anchor plate 50a, which, havingmoved beyond the aforementioned fourth, third and second slides, hasreached the first slide 100a, and, positioned on the related ledge 101bof the track P3 of the same slide 100a, draws the latter along indirection M.

During the stage described above, the aforementioned anchor plate 50a isable to follow the profiles of each track P3, without striking againstany of the ledges 101b of the aforementioned fourth, third and secondslides, in that the rockers 40 of each of the latter, being in contactwith one another, or in contact with the stop 3, are prevented fromrotating and held in position T.

The presence of the first ramps 41a and second ramps 44, and the factthat the movement of the aforementioned anchor plate 50a permits it acertain amount of vertical "elastic excursion", as stated above, causethe first slide 100a to be struck and drawn along as described above,the rocker 40 of the latter, for ledge 101b regarding operation when thecarriage 90 is moving in direction M, being able to freely rotate fromthe first position T to the second position R as a result of thepressure exerted by the same anchor plate 50a upon the first arm 41,which, moving downwards, enables the anchor plate 50a itself to strikethe above-mentioned ledge 101b.

Other anchor plates 50b, 50c, second and third respectively, are shownin the same FIG. 4b, designed to draw along the corresponding second andthird slides 100b, 100c as shown in the following FIG. 4c.

FIG. 4d shows the same first slide 100a drawn along by the correspondingfirst anchor plate 50a, in the last section of its stroke towards thestop 3, with the latter being struck by the boot 43 fixed to the secondarm 42 of the above-mentioned rocker 40 in position R.

As a consequence of the aforesaid second arm 42 striking the stop 3, thesame rocker 40 is made to rotate from the aforementioned second positionR to the first position T.

As a consequence of this, the first arm 41 lifts and disengages theabove-mentioned anchor plate 50a from the related ledge 101b (FIG. 4e).

The following FIG. 4f shows an intermediate stage where the secondanchor plate 50b is disengaged from the corresponding slide 100b, closeto the latter's stopping up against the above-mentioned first slide 100ain the same way as described above.

The above sequence of stages is effected once again, if programmed,during the carriage's stroke in direction S, opposite to direction M,with the related anchor plates striking the slides in the reverse order,from the fourth slide 100d onwards.

The technical advantages conferred by the technical solution describedabove are clear, in particular regarding the possibility of fitting alarge number of slides in the section between two stops, consequentlyoptimising one's use of the carriage's corresponding operating units.

The above-mentioned slides are perfectly identical, which simplifiesboth their production and use; this enables stops of the same kind to beused, it being sufficient for these to be simple brackets.

In addition to this, the special design of the slides, and their relatedrockers, ensures the optimum operation of all the components described,particularly due to the lack of any jamming, possible in known types ofslides using fixed elements.

It is understood that the description supplied herein is solely anunlimited example, such that possible variations to the constructiondetails will not affect the protective framework afforded to theinvention as described above and claimed hereinafter.

What is claimed is:
 1. Improved device for supporting the thread guideof an automatic flat knitting machine, said machine comprising at leastone bar, located parallel to and above needle beds of said machine, acarriage, able to move in a horizontal plane, and fitted with anchorplates, being able to move in a vertical plane, said anchor plates beingable to strike against slides and draw along said slides in directionsof movement of said carriage with said slides mounted so that theycouple with said bar and can be drawn along a section of the said bardelimited by two consecutive stops fixed to the same bar, each of saidslides comprising a body featuring: a horizontal groove in one face ofsaid body and coupling in complementary fashion with said bar; avertical groove on the opposite face of said body, designed to receivean upper portion of a thread guide, said thread guide extending towardssaid needle beds; a track formed by an upper rib of said body, saidtrack featuring a ledge for each direction of movement of said carriage,said ledges being designed to be struck by said anchor plate, in alowered position, for said slide to be drawn along, with said slidecomprising: two rockers, mounted so that they pivot on said body, in asymmetrical position in relation to a plane perpendicular to said bar,each of said rockers working in conjunction with one of said ledges andcomprising two arms, first and second respectively, with said first armextending beside said track, beyond a corresponding ledge towards thecentre of said body, and with said second arm extending downwards by aside of said body, with said rocker able to rotate through apredetermined angle around the axis of said pivot, from a first positionin which said first arm is aligned with said track, and said second armis situated alongside said side to a second position in which said firstarm is lowered and said second arm is moved away from said side, andviceversa; it being possible for said rotation to be alternatively free,actively effected or prevented, said rotation being free, from saidfirst position to said second position, and effected in synchrony withthe striking of said anchor plate first against said first arm and thenagainst said ledge, said rotation being actively effected, from saidsecond position to said first position, as a result of said second armstriking against one of said stops or against said second arm of afurther identical slide, said rotation finally being prevented in saidfirst position as a result of said slide itself being in a stoppedposition with its said second arm stopped up against one of said stopsor against said second arm of another slide.
 2. Device as in claim 1,wherein said rocker features two ramps, first and second respectively,said first ramp being formed in the end of said first arm for enablingmovement over said ledge; and said second ramp being formed between saidfirst and second arms, and sloping in an opposite direction to saidfirst ramp, in order to lead smoothly on to said track.
 3. Device as inclaim 1, wherein the end of said second arm features a boot in ashock-absorbing elastic material.